A New Non-Cu-Oxide Superconductor: (Sr_1-xLn_x)Nb₂O_6-y (Ln: La, Nd, Pr and Ce)

Abstract

A new non-Cu superconductor (Sr 1- x Ln x )Nb 2 O 6- y (Ln: La, Nd, Pr, Ce, Gd and Ho) has been found through resistivity and magnetization measurements. The highest onset transition temperature is about 12 K. Preliminary electron and X-ray diffraction experiments indicate that the crystal structure of the system is orthorhombic with a unit cell of a =11.00 Å, b =7.68 Å and c =5.59 Å, suggesting that the basic crystal structure is an oxygen-deficient CaTa 2 O 6 -type structure.